Vol. 6, No. 4 
Page 3 
Table 3* Deaths among the various strains of pheasants on the Neoga area be¬ 
tween November 1, 1962, and April 30, 1963. Numbers in parentheses are percent¬ 
ages. 
Strains of Pheasants 
Date of Capture 
or Release 
Number Released 
Number Recovered 
Cocks 
Hens 
Cocks 
Hens 
Korean 
March 19, 1963 
81 
127 
19 (23.5) 
23 (18.1) 
Japanese G r een 
March 19, 1963 
40 
24 
6 (lp.0) 
5 (21.0) 
Wild—111inois 
Ma rch 1, 1 563 
None 
83 
None 
15 (17.0) 
Na t i ve 
Fall, 1962 
105 
115 
15*04.3) 
16 (13.9) 
All strains 
226 
354 
40 (17.7) 
59 (16.7) 
Excludes 42 marked native cocks that were, shot during the 19&3 hunting season. 
4. Rab bit Management W. R. Edwards, D. A. Casteel 
Studies of cottontail reproductive behavior and the timing of ovulation and 
subsequent implantation of blastocysts are in progress at study pens located near 
Brownfield Woods in Champaign County. Data obtained in April support the hypo¬ 
thesis that ovulation is induced by the stimulus of copulation in the cottontail. 
On April 24 and 25, a previously unmated female was observed moving along a 
fence following males in the adjacent pen. These males were exhibiting behavior 
which is typically displayed in the presence of a female in estrous. This female 
was introduced into a £-acre pen containing two males at 5:05 PM. She hid in 
heavy cover until the dominant male became active at 7:00 PM. At 7:05, the buck 
located the doe and copulation followed almost immediately. 
The female was collected for histological examination 10 hours following copu¬ 
lation. One ovary contained four ruptured and two mature follicles. The second 
ovary had 4 mature follicles. This evidence suggests that in the cottontail, 
ovulation occurs about 9-11 hours after copulation. This is basically the same 
interval as that for domestic rabbits, Oryctolagus cuniculus , which have been found 
to ovulate 10^- hours after copulation. 
This work is being undertaken in order that bette r criteria can be developed 
for determining pregnancy and reproductive status of female cottontails during 
the period between copulation and implantation of visible embryos. 
5. Responses of Bohwh i tes and Prai rie C 1-1 ■ ckens to Hab i tat Man i pu 1 at ion 
J. A. Ellis, R. J. El ] is 
Three hundred eleven prairie chickens were counted on 29 booming grounds on 10 
census areas distributed throughout the prairie chicken range of south-central 
Illinois during early April, 1563 , Table 4. The booming grounds were located in 
different types of cover in the following numbers and proportions: hay, pasture, 
or grass, 8 (2.8 percent); winter wheat or rye, 5 (17 percent); plowed ground, 4 
